Windows guests - build ISOs including VirtIO drivers

Using Paravirtualized Block Drivers for Windows can dramatically improve Windows guest performance but installing them can be a bit of a fuss. This Tutorial shows you how you can inject all VirtIO drivers into all of your Windows install ISOs in one step using Windows® Automated Installation Kit and some batch files. This makes it really easy to deploy Windows with the most efficient hardware/driver configuration.

Prep Machine

• Launch a fast Windows 7 box and create a folder c:\tmp
• install AIK for Windows 7 (http://www.microsoft.com/en-us/download/details.aspx?id=5753)
• install an ISO editor such as UltraIso
• unpack File:Inject-virtio-drivers.zip batch files to c:\tmp

Prep and extract isos

• copy all your Windows ISOs to folders c:\tmp\win7, c:\tmp\win2008, c:\tmp\win8, c:\tmp\win2012, etc
• extract sources\boot.wim and sources\install.wim from each iso (e.g. by using UltraISO) and put them in the same folder as the iso
• get the latest virtio-win-x.x-xx.iso and extract the drivers into the VirtIO folder for each OS (e.g. WIN8\AMD64\*.* from the iso goes into c:\tmp\win8\VirtIO\ and into c:\tmp\win2012\VirtIO\)

Use AIK

• Start All Programs -> Microsoft Windows AIK -> Deployment Tools Command Prompt (Run as Administrator)
• check how many indices your install.wim has (e.g. dism /get-wiminfo /wimfile:c:\tmp\win2008\install.wim). Windows 2008 has up to 8 indices

 dism /get-wiminfo /wimfile:c:\tmp\win2008\install.wim
 .
 .
 Index : 7
 Name : Windows Server 2008 R2 SERVERWEB
 Description : Windows Server 2008 R2 SERVERWEB
 Size : 10,538,107,020 bytes

 Index : 8
 Name : Windows Server 2008 R2 SERVERWEBCORE
 Description : Windows Server 2008 R2 SERVERWEBCORE
 Size : 3,580,635,107 bytes

 The operation completed successfully.

• Set the variable IDX in each winxxxx-inject.bat to the number of indices you found in each install.wim (e.g. IDX=8)
• For each OS there is a SetupComplete.cmd. This script is always executed by the Windows installation as a final step. Make sure it contains the ballon service installer. You may add other commands to it.

Inject drivers and write wim files back to isos

• launch multiple winxxxx-inject.bat sequentially and uninterrupted, e.g.: winpe-inject.bat && win7-inject.bat etc.

winpe-inject.bat && win7-inject.bat && win2008-inject.bat && win8-inject.bat && win2012-inject.bat

• alternatively you can run multiple batch commands in parallel by launching multiple instances of "Deployment Tools Command Prompt" as Administrator
• for each iso use UltraISO to copy boot.wim and install.wim back to the sources folder of the ISO file

Example batch file win2012-inject.bat

@echo off

set MyOS=win2012
set IDX=4

if not exist c:\tmp\%MyOS%\virtio\blnsvr.exe (echo Please copy the VirtIO drivers to c:\tmp\%MyOS%\VirtIO\ first && goto :eof)

rem **********(1,1,2) means 2 loops *************************
FOR /L %%i IN (1,1,2) DO (
  ECHO Prepping %MyOS% boot.wim - Index %%i
  if not exist c:\tmp\%MyOS%\bootwim\%%i mkdir c:\tmp\%MyOS%\bootwim\%%i
  imagex /mountrw c:\tmp\%MyOS%\boot.wim %%i c:\tmp\%MyOS%\bootwim\%%i
  dism /image:c:\tmp\%MyOS%\bootwim\%%i /add-driver /driver:c:\tmp\%MyOS%\virtio /Recurse /ForceUnsigned
  imagex /unmount /commit c:\tmp\%MyOS%\bootwim\%%i
)


FOR /L %%i IN (1,1,%IDX%) DO (
  ECHO Prepping %MyOS% install.wim - Index %%i
  if not exist c:\tmp\%MyOS%\installwim\%%i mkdir c:\tmp\%MyOS%\installwim\%%i
  imagex /mountrw c:\tmp\%MyOS%\install.wim %%i c:\tmp\%MyOS%\installwim\%%i
  dism /image:c:\tmp\%MyOS%\installwim\%%i /add-driver /driver:c:\tmp\%MyOS%\virtio /Recurse /ForceUnsigned
  xcopy /Y c:\tmp\%MyOS%\VirtIO "C:\tmp\%MyOS%\installwim\%%i\Program Files\VirtIO\"
  xcopy /Y c:\tmp\%MyOS%\SetupComplete.cmd "C:\tmp\%MyOS%\installwim\%%i\Windows\Setup\Scripts\"
  imagex /unmount /commit c:\tmp\%MyOS%\installwim\%%i
)

:eof

Additional Info

Now that you have changed all your ISO files to include Paravirtualized drivers you no longer need IDE drives or a E1000 network adapter. Always select VirtIO for the Disk Controller and VirtIO when selecting a network card in the Creation Wizard.

See also

• Windows 2012 guest best practices
• Windows 2008 guest best practices